Eru grows bored of the club's lack of activities, and suggests that they prepare an anthology to submit for the school's culture festival in the fall. While tracking down previous anthologies, the club discovers a mystery in the school's library.

Over coffee, Eru opens up to Oreki to explain why she joined the club, and asks him for his help with a personal matter. Still unable to locate any anthologies, the club members run into an obstacle when trying to search the club's previous room.

Hotaro is torn between continuing with his "gray" life and the "rosy" life that the others live. A phone call from Hotaro's sister leads him to believe that there are pieces missing to his theory regarding the events of Sekitani's expulsion.

Hotaro's sister returns home, and sets her lethargic brother up with a temporary job filling in as a lifeguard at the city pool. Satoshi invites Eru and Mayaka out to see Hotaro at work, and the group stumble upon a minor mystery to be solved.

It is the first day of the school culture festival, and the club members look forward to it with both longing and dread. They must come up with a way to sell all of the copies of "Hyouka" that were printed, as dauntless as the task seems.

Satoshi is ready for Jumoji to strike, but when the anticipated target is passed over, he must reconsider his strategy. Tomoe gives Hotaro a copy of "A Corpse By Evening," and Eru notices that the art style is similar to one she has seen elsewhere.

While in middle school, Satoshi rejected Mayaka's Valentine chocolate, so this year, she works even harder to present him with a Valentine's Day masterpiece. But when it turns up missing, the search is on to discover what happened to it.